"In three days of testimony, Judge Roberts gave no reason for optimism that he would vote to uphold a woman's right to choose," the National Women's Law Center said in a memo circulated Monday, part of a sustained effort by liberal groups to maximize Democratic opposition to the nomination.

"There's been extensive outreach to senators and their staffs by numerous people urging them to vote no on the nomination," added Nan Aron, who heads the Alliance for Justice, another organization that spent the weekend trying to line up "no" votes.

The Senate Judiciary Committee is to vote on Roberts on Thursday, and the decisions made by the panel's eight Democrats - including two members of the party's leadership - will provide the first indication of whether the 50-year-old appeals court judge and former Reagan administration lawyer can command significant bipartisan support.

Whatever Democrats decide, Roberts' confirmation to succeed the late Chief Justice William H. Rehnquist is all but secured, given widespread, possibly unanimous support among the Senate's 55 Republicans.

Sen. Arlen Specter of Pennsylvania, who presided over confirmation hearings as chairman of the Judiciary Committee, underscored the depth of the GOP support during the day when he formally announced his plans to support the nominee.

"Most importantly, Judge Roberts' answers demonstrated that he would take a fair, non-ideological approach to the law," Specter said.

Thus far, all 44 Senate Democrats have remained publicly neutral on the nomination, acceding to the request of the party's leader, Sen. Harry Reid of Nevada, to avoid commitments until hearings were completed.